マーチソン隕石からの低分子量炭化水素とモノカーボキシル酸の炭素同位体組成
G Yuen1, N Blair, D J Des Marais
1Department of Chemistry, Arizona State University,Tempe 85287, USA.
Nature
|January 19, 1984
まとめ
隕石に含まれる有機物質の起源は不明です. マーチソン隕石の炭化水素と炭酸塩酸の炭素同位体分析は,地球外の起源を明らかにし,これらの化合物の類似の形成経路を示唆しています.
科学分野:
- 宇宙化学 (コスモケミストリー)
- オーガニック・ジオケミストリー オーガニック・ジオケミストリー
- イソトープ地球化学 イソトープ地球化学
背景:
- 炭酸性隕石の有機物質の起源は,長年にわたる科学的な議論である.
- 隕石の有機化合物を理解することで,初期の太陽系化学の洞察が得られます.
研究 の 目的:
- 隕石における有機物質の起源を調査する.
- マーチソン隕石の特定の有機分子の炭素同位体組成を分析するために.
主な方法:
- 炭素同位体組成は,個々の炭化水素とモノカーボキシル酸の組成を測定する.
- マーチソン隕石 (C2炭酸コンドライト) のサンプル分析.
主要な成果:
- マーチソン隕石からの大抵の揮発性有機産物は,同位体的に地上の同位体よりも重いので,地外起源を示している.
- 炭化水素と炭酸の両方について,炭素数を増やして炭素13と炭素12の比率が低下する並列の傾向が観察されました.
- カーボキシル酸は,同じ炭素数を持つ炭化水素よりも高い同位素比を示した.
結論:
- 観測された同位体傾向は,運動的に制御された合成を支持し,隕石の炭化水素と炭酸塩酸の同様の生産機構を示唆しています.
- この発見は,地球外の有機合成に関与する前駆体種のアイデンティティに制約を与える.
- この研究は,宇宙における有機分子の無生物的形成を理解するのに寄与する.
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